How Do Stablecoins Maintain Their Peg?

A stablecoin peg is the target price a stablecoin is designed to hold. For the vast majority of stablecoins, this target is one U.S. dollar. Stablecoins maintain that price through two mechanisms. The first is reserves or collateral that give each token its underlying value; the second is an arbitrage process that returns the market price to the peg whenever it deviates from it.

In this article, we’ll take a closer look at each method and the major stablecoins that make use of each.

What is a Stablecoin Peg?

A stablecoin peg is the reference price a stablecoin is designed to track. A U.S. Dollar stablecoin tracks one USD, a Euro stablecoin tracks one Euro, most gold-pegged stablecoins track one troy ounce of physical gold, and so on. For the purposes of this article, we’ll mostly be discussing USD-pegged stablecoins, the largest variety by far with over 98% of the total market share as of mid-2026.

Expand Chart

Most stablecoins operate with soft pegs, meaning the price floats within a very narrow price band rather than being fixed rigidly to the reference price. This means minor deviations, such as $0.998 or $1.002, can occur. These are entirely normal and typically negligible for everyday trading and holding purposes.

On the other hand, a depeg is when a token deviates far from its one-dollar price and remains there for an extended period of time. When a stablecoin depegs, it means the mechanism responsible for restoring the price back to peg has stopped working. 

In some cases, arbitrage traders will step in to restore the stabelcoin to its reference value and profit from the price move. However, several past incidents have seen stablecoins fail to recover after a depegging event, such as in the case of the TerraUSD (UST) collapse in 2022.

How Do Stablecoins Maintain Their Peg?

Centralized stablecoins are the most common type. These assets are issued by a central company, who also holds on to a stockpile of cash (and cash equivalent assets like short-term U.S. treasury bonds) which backs up the tokens it issues on the blockchain. For example, each USDC onchain is backed up 1:1 by assets in the reserves of the issuer, Circle. 

Therefore, the price of USDC stays pegged to $1 because market participants have confidence that the company can honor redemptions, exchanging stablecoins for dollars on demand. The stablecoin represents a digitized claim on a real-world asset, and so it holds the same value as that asset. This combination of 1:1 reserves and efficient redemptions allows the coin to hold its peg.

Meanwhile, arbitrage opportunities incentivize arbitrageurs to close any small deviations a stablecoin may experience in its market price. For example, if a stablecoin is trading in the open market for $0.99, an arbitrageur can buy all available stablecoins at that price, causing the market price to rise back to $1. They can then redeem every bought stablecoin with the issuer for one dollar, thereby profiting from the one-cent spread.

It is worth noting that both factors complement one another, because a token with sufficient reserves but no functioning redemption process, or vice versa, can still depeg.

The Main Types of Stablecoin Peg Mechanisms

There are four main types of stablecoins, each with different mechanisms in how they maintain their pegs.

Fiat-Collateralized Stablecoins

Fiat-collateralized stablecoins are stablecoins backed 1:1 with cash and cash-equivalent assets held in their reserves. This is the most popular and straightforward type of stablecoin, with examples including Tether’s USDT and Circle’s USDC.

The peg is maintained through direct redemption, where holders can provide fiat to the issuer and receive stablecoins, or redeem a stablecoin for fiat. The vulnerability of fiat-collateralized stablecoins is the reserve itself, because if the underlying assets were to become inaccessible, redemptions may halt even when the stablecoin remains fully backed on paper.

Crypto-Collateralized Stablecoins

Crypto-collateralized stablecoins are backed by other crypto assets locked in smart contracts, and they preserve their value by requiring more collateral than the value of the coins they issue. Sky (formerly MakerDAO) operates the largest of these, with two linked tokens, USDS and DAI.

To mint a crypto-collateralized stablecoin, a user has to deposit crypto assets with a value larger than the amount of stablecoins being borrowed. Because crypto assets are generally volatile, the extra value or “overcollateralization” acts as protection against any price declines in the collateral. If the value of the collateral were to fall below a threshold, smart contracts would automatically sell (liquidate) the collateral to ensure the issuer incurs no net loss.

Algorithmic Stablecoins

Algorithmic stablecoins are designed to hold a peg through code and incentives rather than reserves. Algorithmic stablecoins often rely on a dual-token system: a separate, unpegged token absorbs price pressure. For example, when the stablecoin falls below a dollar, holders can burn it to mint the volatile token, thereby contracting the supply of the stablecoin to raise its price back to peg.

Terra’s UST was the most prominent example of an algorithmic stablecoin, as well as a stark warning of how volatility can cause these systems to quickly spiral out of control. In May 2022, UST lost its dollar peg and erased over $18 billion in value over three days, as holders rushed to redeem. Meanwhile, its second token, LUNA, inflated toward zero. The algorithmic mechanism accelerated the collapse as it fell into a death spiral.

Expand Chart

Synthetic (Delta-Neutral) Stablecoins

Synthetic stablecoins hold their peg through a hedged trading position rather than a reserve of assets. Ethena’s USDe is the largest example of a synthetic stablecoin. The mechanism works as follows:

• For every dollar of crypto collateral it holds, Ethena opens an equal and opposite short perpetual futures position. 
• When the collateral falls in value, the short position gains an approximately equal amount, so the combined position is neutral. 
• This mechanism also generates yield from perpetual funding payments, which accounts for much of USDe’s appeal.

However, it is worth noting that funding payments can turn negative. If funding rates remain negative for a prolonged period of time, the short perpetual futures leg of the delta-neutral position becomes a cost rather than a source of yield.

In Ethena’s case, they have a reserve fund to absorb such periods. However, it’s unclear  how long a period of sustained negative funding rates that reserve is adequate for; no synthetic dollar of this scale has operated through a full, multi-year bear market. 

Real Examples of Stablecoin Depegs

Each significant stablecoin depeg in the past has occurred due to at least one of the aforementioned factors.

USDC, March 2023. Circle disclosed that $3.3 billion of USDC’s reserves were held at the collapsed Silicon Valley Bank. The funds were almost entirely recovered within days, but over the intervening weekend, holders had no certainty of that outcome, which caused USDC depeg to $0.87 before recovering once redemptions were confirmed.

TerraUSD, May 2022. The algorithmic model unwound in the death spiral described previously, erasing roughly $18 billion in market value. No reserves stood behind the token once the incentive loop reversed. This means the value held in the UST stablecoin was simply erased.

How Regulation Affects The Stability of a Stablecoin’s Peg

The GENIUS Act, signed in July 2025, is the first federal framework for payment stablecoins in the United States. Under the act, stablecoin issuers are required to back every token 1:1 with cash and cash equivalents, publish monthly reserve disclosures, and be able to redeem on demand. Stablecoins are also prohibited from paying interest or yield to holders.

However, while regulation reduces the likelihood of a reserve-driven depeg, it does not address the designs that fall outside its scope. For example, a regulatory framework can require fiat reserves to remain liquid, but cannot ensure that a delta-neutral hedge or an overcollateralized vault performs as intended during a market crisis.

Frequently Asked Questions

1. What does it mean when a stablecoin loses its peg?

It means the stablecoin’s market price has moved meaningfully away from its intended reference price for an extended period of time. Deviations of a fraction of a cent are normal, but if a dollar stablecoin sits at $0.90 for days, or even hours, this indicates that the backing or the confidence behind the coin has broken.

2. How do stablecoins stay close to one dollar?

The market price of a stablecoin trades within a very narrow price band around one dollar, rather than at exactly a dollar. A stablecoin’s reserves provide its underlying value, while arbitrage corrects any market deviations.

3. Are algorithmic stablecoins safe?

Purely algorithmic models are generally considered unsafe and have a weak track record. Terra’s UST was the largest example and collapsed in May 2022 when its incentive loop reversed into a death spiral.

4. Can a fully backed stablecoin still lose its peg?

Yes. The most famous example of this was USDC temporarily losing its peg in March 2023 as a portion of its reserves were frozen in the collapsed Silicon Valley Bank.

5. Which type of stablecoin peg is the most reliable?

Fiat-backed stablecoins have proven to be the most reliable, which is the model the GENIUS Act is built around.

6. How does the GENIUS Act affect stablecoin pegs?

It establishes the requirements that keep a fiat-backed peg credible: one-to-one reserves in cash and short-term Treasuries, monthly disclosures, and redemption on demand.